1 files changed, 448 insertions, 0 deletions

diff --git a/drivers/char/snsc.c b/drivers/char/snsc.c
new file mode 100644
index 000000000000..ffb9143376bb
--- /dev/null
+++ b/drivers/char/snsc.c
@@ -0,0 +1,448 @@
+/*
+ * SN Platform system controller communication support
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2004 Silicon Graphics, Inc. All rights reserved.
+ */
+
+/*
+ * System controller communication driver
+ *
+ * This driver allows a user process to communicate with the system
+ * controller (a.k.a. "IRouter") network in an SGI SN system.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/device.h>
+#include <linux/poll.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <asm/sn/io.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/module.h>
+#include <asm/sn/geo.h>
+#include <asm/sn/nodepda.h>
+#include "snsc.h"
+
+#define SYSCTL_BASENAME "snsc"
+
+#define SCDRV_BUFSZ     2048
+#define SCDRV_TIMEOUT   1000
+
+static irqreturn_t
+scdrv_interrupt(int irq, void *subch_data, struct pt_regs *regs)
+{
+        struct subch_data_s *sd = subch_data;
+        unsigned long flags;
+        int status;
+
+        spin_lock_irqsave(&sd->sd_rlock, flags);
+        spin_lock(&sd->sd_wlock);
+        status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
+
+        if (status > 0) {
+                if (status & SAL_IROUTER_INTR_RECV) {
+                        wake_up(&sd->sd_rq);
+                }
+                if (status & SAL_IROUTER_INTR_XMIT) {
+                        ia64_sn_irtr_intr_disable
+                            (sd->sd_nasid, sd->sd_subch,
+                             SAL_IROUTER_INTR_XMIT);
+                        wake_up(&sd->sd_wq);
+                }
+        }
+        spin_unlock(&sd->sd_wlock);
+        spin_unlock_irqrestore(&sd->sd_rlock, flags);
+        return IRQ_HANDLED;
+}
+
+/*
+ * scdrv_open
+ *
+ * Reserve a subchannel for system controller communication.
+ */
+
+static int
+scdrv_open(struct inode *inode, struct file *file)
+{
+        struct sysctl_data_s *scd;
+        struct subch_data_s *sd;
+        int rv;
+
+        /* look up device info for this device file */
+        scd = container_of(inode->i_cdev, struct sysctl_data_s, scd_cdev);
+
+        /* allocate memory for subchannel data */
+        sd = kmalloc(sizeof (struct subch_data_s), GFP_KERNEL);
+        if (sd == NULL) {
+                printk("%s: couldn't allocate subchannel data\n",
+                       __FUNCTION__);
+                return -ENOMEM;
+        }
+
+        /* initialize subch_data_s fields */
+        memset(sd, 0, sizeof (struct subch_data_s));
+        sd->sd_nasid = scd->scd_nasid;
+        sd->sd_subch = ia64_sn_irtr_open(scd->scd_nasid);
+
+        if (sd->sd_subch < 0) {
+                kfree(sd);
+                printk("%s: couldn't allocate subchannel\n", __FUNCTION__);
+                return -EBUSY;
+        }
+
+        spin_lock_init(&sd->sd_rlock);
+        spin_lock_init(&sd->sd_wlock);
+        init_waitqueue_head(&sd->sd_rq);
+        init_waitqueue_head(&sd->sd_wq);
+        sema_init(&sd->sd_rbs, 1);
+        sema_init(&sd->sd_wbs, 1);
+
+        file->private_data = sd;
+
+        /* hook this subchannel up to the system controller interrupt */
+        rv = request_irq(SGI_UART_VECTOR, scdrv_interrupt,
+                         SA_SHIRQ | SA_INTERRUPT,
+                         SYSCTL_BASENAME, sd);
+        if (rv) {
+                ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch);
+                kfree(sd);
+                printk("%s: irq request failed (%d)\n", __FUNCTION__, rv);
+                return -EBUSY;
+        }
+
+        return 0;
+}
+
+/*
+ * scdrv_release
+ *
+ * Release a previously-reserved subchannel.
+ */
+
+static int
+scdrv_release(struct inode *inode, struct file *file)
+{
+        struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+        int rv;
+
+        /* free the interrupt */
+        free_irq(SGI_UART_VECTOR, sd);
+
+        /* ask SAL to close the subchannel */
+        rv = ia64_sn_irtr_close(sd->sd_nasid, sd->sd_subch);
+
+        kfree(sd);
+        return rv;
+}
+
+/*
+ * scdrv_read
+ *
+ * Called to read bytes from the open IRouter pipe.
+ *
+ */
+
+static inline int
+read_status_check(struct subch_data_s *sd, int *len)
+{
+        return ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch, sd->sd_rb, len);
+}
+
+static ssize_t
+scdrv_read(struct file *file, char __user *buf, size_t count, loff_t *f_pos)
+{
+        int status;
+        int len;
+        unsigned long flags;
+        struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+
+        /* try to get control of the read buffer */
+        if (down_trylock(&sd->sd_rbs)) {
+                /* somebody else has it now;
+                 * if we're non-blocking, then exit...
+                 */
+                if (file->f_flags & O_NONBLOCK) {
+                        return -EAGAIN;
+                }
+                /* ...or if we want to block, then do so here */
+                if (down_interruptible(&sd->sd_rbs)) {
+                        /* something went wrong with wait */
+                        return -ERESTARTSYS;
+                }
+        }
+
+        /* anything to read? */
+        len = CHUNKSIZE;
+        spin_lock_irqsave(&sd->sd_rlock, flags);
+        status = read_status_check(sd, &len);
+
+        /* if not, and we're blocking I/O, loop */
+        while (status < 0) {
+                DECLARE_WAITQUEUE(wait, current);
+
+                if (file->f_flags & O_NONBLOCK) {
+                        spin_unlock_irqrestore(&sd->sd_rlock, flags);
+                        up(&sd->sd_rbs);
+                        return -EAGAIN;
+                }
+
+                len = CHUNKSIZE;
+                set_current_state(TASK_INTERRUPTIBLE);
+                add_wait_queue(&sd->sd_rq, &wait);
+                spin_unlock_irqrestore(&sd->sd_rlock, flags);
+
+                schedule_timeout(SCDRV_TIMEOUT);
+
+                remove_wait_queue(&sd->sd_rq, &wait);
+                if (signal_pending(current)) {
+                        /* wait was interrupted */
+                        up(&sd->sd_rbs);
+                        return -ERESTARTSYS;
+                }
+
+                spin_lock_irqsave(&sd->sd_rlock, flags);
+                status = read_status_check(sd, &len);
+        }
+        spin_unlock_irqrestore(&sd->sd_rlock, flags);
+
+        if (len > 0) {
+                /* we read something in the last read_status_check(); copy
+                 * it out to user space
+                 */
+                if (count < len) {
+                        pr_debug("%s: only accepting %d of %d bytes\n",
+                                 __FUNCTION__, (int) count, len);
+                }
+                len = min((int) count, len);
+                if (copy_to_user(buf, sd->sd_rb, len))
+                        len = -EFAULT;
+        }
+
+        /* release the read buffer and wake anyone who might be
+         * waiting for it
+         */
+        up(&sd->sd_rbs);
+
+        /* return the number of characters read in */
+        return len;
+}
+
+/*
+ * scdrv_write
+ *
+ * Writes a chunk of an IRouter packet (or other system controller data)
+ * to the system controller.
+ *
+ */
+static inline int
+write_status_check(struct subch_data_s *sd, int count)
+{
+        return ia64_sn_irtr_send(sd->sd_nasid, sd->sd_subch, sd->sd_wb, count);
+}
+
+static ssize_t
+scdrv_write(struct file *file, const char __user *buf,
+            size_t count, loff_t *f_pos)
+{
+        unsigned long flags;
+        int status;
+        struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+
+        /* try to get control of the write buffer */
+        if (down_trylock(&sd->sd_wbs)) {
+                /* somebody else has it now;
+                 * if we're non-blocking, then exit...
+                 */
+                if (file->f_flags & O_NONBLOCK) {
+                        return -EAGAIN;
+                }
+                /* ...or if we want to block, then do so here */
+                if (down_interruptible(&sd->sd_wbs)) {
+                        /* something went wrong with wait */
+                        return -ERESTARTSYS;
+                }
+        }
+
+        count = min((int) count, CHUNKSIZE);
+        if (copy_from_user(sd->sd_wb, buf, count)) {
+                up(&sd->sd_wbs);
+                return -EFAULT;
+        }
+
+        /* try to send the buffer */
+        spin_lock_irqsave(&sd->sd_wlock, flags);
+        status = write_status_check(sd, count);
+
+        /* if we failed, and we want to block, then loop */
+        while (status <= 0) {
+                DECLARE_WAITQUEUE(wait, current);
+
+                if (file->f_flags & O_NONBLOCK) {
+                        spin_unlock(&sd->sd_wlock);
+                        up(&sd->sd_wbs);
+                        return -EAGAIN;
+                }
+
+                set_current_state(TASK_INTERRUPTIBLE);
+                add_wait_queue(&sd->sd_wq, &wait);
+                spin_unlock_irqrestore(&sd->sd_wlock, flags);
+
+                schedule_timeout(SCDRV_TIMEOUT);
+
+                remove_wait_queue(&sd->sd_wq, &wait);
+                if (signal_pending(current)) {
+                        /* wait was interrupted */
+                        up(&sd->sd_wbs);
+                        return -ERESTARTSYS;
+                }
+
+                spin_lock_irqsave(&sd->sd_wlock, flags);
+                status = write_status_check(sd, count);
+        }
+        spin_unlock_irqrestore(&sd->sd_wlock, flags);
+
+        /* release the write buffer and wake anyone who's waiting for it */
+        up(&sd->sd_wbs);
+
+        /* return the number of characters accepted (should be the complete
+         * "chunk" as requested)
+         */
+        if ((status >= 0) && (status < count)) {
+                pr_debug("Didn't accept the full chunk; %d of %d\n",
+                         status, (int) count);
+        }
+        return status;
+}
+
+static unsigned int
+scdrv_poll(struct file *file, struct poll_table_struct *wait)
+{
+        unsigned int mask = 0;
+        int status = 0;
+        struct subch_data_s *sd = (struct subch_data_s *) file->private_data;
+        unsigned long flags;
+
+        poll_wait(file, &sd->sd_rq, wait);
+        poll_wait(file, &sd->sd_wq, wait);
+
+        spin_lock_irqsave(&sd->sd_rlock, flags);
+        spin_lock(&sd->sd_wlock);
+        status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
+        spin_unlock(&sd->sd_wlock);
+        spin_unlock_irqrestore(&sd->sd_rlock, flags);
+
+        if (status > 0) {
+                if (status & SAL_IROUTER_INTR_RECV) {
+                        mask |= POLLIN | POLLRDNORM;
+                }
+                if (status & SAL_IROUTER_INTR_XMIT) {
+                        mask |= POLLOUT | POLLWRNORM;
+                }
+        }
+
+        return mask;
+}
+
+static struct file_operations scdrv_fops = {
+        .owner =        THIS_MODULE,
+        .read =         scdrv_read,
+        .write =        scdrv_write,
+        .poll =         scdrv_poll,
+        .open =         scdrv_open,
+        .release =      scdrv_release,
+};
+
+/*
+ * scdrv_init
+ *
+ * Called at boot time to initialize the system controller communication
+ * facility.
+ */
+int __init
+scdrv_init(void)
+{
+        geoid_t geoid;
+        cnodeid_t cnode;
+        char devname[32];
+        char *devnamep;
+        struct sysctl_data_s *scd;
+        void *salbuf;
+        struct class_simple *snsc_class;
+        dev_t first_dev, dev;
+
+        if (alloc_chrdev_region(&first_dev, 0, numionodes,
+                                SYSCTL_BASENAME) < 0) {
+                printk("%s: failed to register SN system controller device\n",
+                       __FUNCTION__);
+                return -ENODEV;
+        }
+        snsc_class = class_simple_create(THIS_MODULE, SYSCTL_BASENAME);
+
+        for (cnode = 0; cnode < numionodes; cnode++) {
+                        geoid = cnodeid_get_geoid(cnode);
+                        devnamep = devname;
+                        format_module_id(devnamep, geo_module(geoid),
+                                         MODULE_FORMAT_BRIEF);
+                        devnamep = devname + strlen(devname);
+                        sprintf(devnamep, "#%d", geo_slab(geoid));
+
+                        /* allocate sysctl device data */
+                        scd = kmalloc(sizeof (struct sysctl_data_s),
+                                      GFP_KERNEL);
+                        if (!scd) {
+                                printk("%s: failed to allocate device info"
+                                       "for %s/%s\n", __FUNCTION__,
+                                       SYSCTL_BASENAME, devname);
+                                continue;
+                        }
+                        memset(scd, 0, sizeof (struct sysctl_data_s));
+
+                        /* initialize sysctl device data fields */
+                        scd->scd_nasid = cnodeid_to_nasid(cnode);
+                        if (!(salbuf = kmalloc(SCDRV_BUFSZ, GFP_KERNEL))) {
+                                printk("%s: failed to allocate driver buffer"
+                                       "(%s%s)\n", __FUNCTION__,
+                                       SYSCTL_BASENAME, devname);
+                                kfree(scd);
+                                continue;
+                        }
+
+                        if (ia64_sn_irtr_init(scd->scd_nasid, salbuf,
+                                              SCDRV_BUFSZ) < 0) {
+                                printk
+                                    ("%s: failed to initialize SAL for"
+                                     " system controller communication"
+                                     " (%s/%s): outdated PROM?\n",
+                                     __FUNCTION__, SYSCTL_BASENAME, devname);
+                                kfree(scd);
+                                kfree(salbuf);
+                                continue;
+                        }
+
+                        dev = first_dev + cnode;
+                        cdev_init(&scd->scd_cdev, &scdrv_fops);
+                        if (cdev_add(&scd->scd_cdev, dev, 1)) {
+                                printk("%s: failed to register system"
+                                       " controller device (%s%s)\n",
+                                       __FUNCTION__, SYSCTL_BASENAME, devname);
+                                kfree(scd);
+                                kfree(salbuf);
+                                continue;
+                        }
+
+                        class_simple_device_add(snsc_class, dev, NULL,
+                                                "%s", devname);
+
+                        ia64_sn_irtr_intr_enable(scd->scd_nasid,
+                                                 0 /*ignored */ ,
+                                                 SAL_IROUTER_INTR_RECV);
+        }
+        return 0;
+}
+
+module_init(scdrv_init);